From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: ifreq flags or ioctl calls to turn an interface down?
Date: Thu, 12 May 2011 15:32:23 +0200
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To: Chin Shi Hong <cshong87@gmail.com>
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Le jeudi 12 mai 2011 =C3=A0 21:27 +0800, Chin Shi Hong a =C3=A9crit :
> Dear all,
>=20
> I am developing an application that will turn a network interface dow=
n
> (something like command "ifconfig <network interface> down".
>=20
> What are the ifreq flags or ioctl calls to turn a network interface d=
own?
>=20
> Or is there any other way to implement this feature into my applicati=
on?

Quick answer :

strace ifconfig eth2 down

=2E..
socket(PF_INET, SOCK_DGRAM, IPPROTO_IP) =3D 4

ioctl(4, SIOCGIFFLAGS, {ifr_name=3D"eth2", ifr_flags=3DIFF_UP|IFF_BROAD=
CAST|
IFF_RUNNING|IFF_MULTICAST}) =3D 0

ioctl(4, SIOCSIFFLAGS, {ifr_name=3D"eth2", ifr_flags=3DIFF_BROADCAST|
IFF_RUNNING|IFF_MULTICAST}) =3D 0